Timer0_PWM.h

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/*
**
****************************************************************************
**
**
**             Copyright (c) 2007 - Atmel Corporation
**             Proprietaty Information
**
** Project     : ATMEGA88 + ATA6824 High Temperature H-bridge System
** Module      : Timer0_PWM.h
** Description : High temperature DC motor control
**                PWM output compare OC0B pluged on ATA6824 PWM input command
**
** Version :     Date:         Author:      Comment:
**    1.0        26.01.2007    F.G.          Creation 
**
** LICENSE -
**
** ATMEL - 2007
** All software programs are provided 'as is' without warranty of any kind:
** Atmel does not state the suitability of the provided materials for any
** purpose. Atmel hereby disclaim all warranties and conditions with regard
** to the provided software, including all implied warranties, fitness for
** a particular purpose, title and non-infringement.In no event will Atmel
** be liable for any indirect or consequential damages or any damages
** whatsoever resulting from the usage of the software program.
****************************************************************************
**
*/

#ifndef _TIMER0_PWM_H
#define _TIMER0_PWM_H
/*_____ I N C L U D E S ____________________________________________________*/

/*_____ M A C R O S ________________________________________________________*/

#define TIMER0_SET_OC0B_PWM(val)          (OCR0B = val)

/*_____ D E F I N I T I O N S ______________________________________________*/

typedef struct{
  U16 count :15;      
  U16 ovf   :1;       
}SoftTimer_t;
                
#define WD_TIME_TRIG  320     // 320 * 32µs --> 10.24ms, half of the WD refresh period. 
                              // A 51 Kohms resistor is pluged to the ATA6824 Rwd pin
                              // Which lead to a typical 25ms Twd (see ATA6824 datasheet §5.3)
                              // A rising edge on the WD trigger pin should occur 
                              // in t2 open window, which is: (25ms - 9.61ms) < Trigger < 25ms

#define ONE_SECOND    31250   // 31250 * 32µs --> 1s period counter

#define DISABLE_OCB0()    (TCCR0A &= ~(1<<COM0B1) | (1<<COM0B0))
#define RE_ENABLE_OCB0()  (TCCR0A |=  (1<<COM0B1))

/*_____ P R O T O T Y P E S - D E C L A R A T I O N ________________________*/

void Timer0_start(void);              // Start Timer 0 for PWM using Output compare, 32µs overflow period
void manage_time_base(void);          // Check Timer 0 overflows to manage time base 

/*_____ G L O B A L S ______________________________________________________*/

extern SoftTimer_t time_count_1s;     // variable used to decrement to zero each elapsed second
#endif //_TIMER0_PWM_H

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